Shock absorber



5 Sheets-Sheet l May 1.9, 1931. -c. N. MITCHELL SHOCK ABSORBER ignal Filed May 26, 1924 c. N. MITCHELL 1,805,836

SHOCK ABSORBER May 19, 1931.

3 Sheets-Sheet 2 Original F'iled May 26, 1924 vSHOCK ABSORBER Original Filed May 26, 1924 3 Sheets-Sheet 3 Patented May 19, 1931 f.

STATES COURTE N. MITCHELL, OF CLEVELAND HEIGHTS, OHIO SHOCK ABASORBER Original application led May 26, 1924, Serial No. 715,852. `vlDivide. and this application filed November 2,

This invention relates, as indicated, to shock absorbers, referring more particularly tothat type ot shockabsorber which is adapted to be interposed' betweenk an automobile trame or chassis and the axle to brake the rebound of the frame, as when it moves upwardly'away from the axle. In general practice the shock absorber and its enclosure is mounted on the frame of an automobile above the axle, and the braking mechanism thereof connected by a strap, or other suitable means, to the axle. The objectoif this invention is'to provide in a shock absorber of the above described character an improved mechanism for braking or retarding suoli rebound, which mechanism is contained by, and operable upon, the interior vof an enclosing casing or brake drum. The same permits the use of approximately the .entire 'outer dimension of i@ the shoclrabsorber casingfor the application of the braking means, thus providing a selfco'nt-ained unit of minimum dimensions.

A further object is to provide a shock absorber which is adapted to operate to brake the shock of the movement of the axle toward thervehicle frame, as well as to retard movementV of the axle in the opposite direction, it being of course desirable to have the braking action of the shock absorber of much 33 lesser degree when the axle is moving upward than when the frame rebounds therefrom. v I Y Another object of `my invention is to provide an inexpensive, simplified type of connecting means'which is adapted to connect the'operating mechanism of the shock absorber to theaxle of a vehicle. To the accomplishment/oi: the foregoing and related ends, said invention., then, consists of the means 'hereinafter fully described and particularly pointed out in the claims.

' This application constitutes a division of.

my co-pendingapplication Serial No. 715,852,

y, filed- May 26, 1924, now Patent No. 1,699,707. AJ) The annexed drawings and the following.

description set forthzin detail certain mechanism'embodying the invention, such disclosed means constituting, however, butone of various mechanical forms ln'vvhich the prin cipie of the invention may be used.

Vframe and axle illustrating the manner of yhicle frame or chassis 11 by any suitable Serial No. 316,772.

In said' annexed drawings Fig. 1 is a sectional view of my novel shock absorber; l Fig. 2 is a transverse axial sectional view of the absorber taken on line 2 2, in Fig. 1; Figs. 3 and 4 are views similar to Figs. 1 and 2 of a modified type of the invention, said iigures being taken on lines 3 3, in Fig. 4,` and 4--4 in Fig. 3, respectively;

Fig. is a fragmentary view of a vehicle attachment of the present shock absorber shown in Figs. 1 and 2; Fig. 6 is a view similar to Fig. 2 showing a modified construction. Fig. 7 is a sectional view taken on the line 7 7 in Fig. 8; and

Fig. 8 is a diagrammatic view illustrating the convergence between the brake drum and shoey pivotal bearing of this invention.

VReferring'now to the embodiment oimy invention .illustrated in Figs. 1, 2 and 6, 1() designates a flanged hub member which is adapted to be attached to the `side of a vemeans, such as a bolt 12. The bolt 12 herein is screw threaded in the hub 10-and has its forward end projecting `through a hollow boss portion 14, integrally formed on the i'iontside oit' member 10. Enclosing the outer end of boss 14 is a flanged brake drum 15, which is rotatably held by suitable means, to be presently described so as to be cirfcuin-` erentially movable with respect to theaxis of the hub boss 14 and the boltv12. The drum oonsistsof an annular flange or brake band 16, against the inner surfacek of which the shock absorbing or braking mechanism of this invention frictionally engages,and of a vertical fron't side 17.

As is usuall inthe present type of shock absorbers, the braking action; of they various mechanisms result from the rotation of the drum band 16 in one direction. During the reverse movement of such band the brake means are automatically rendered inoperative. Many designs, of'connections mayy be utilized for connecting the drum 15 to the axle 18 of an automobile, so that when in use, as the asile is moved toward and away from the $.99

be secured around the outer surface of theY drum band 16.

As has been heretofore stated the braking mechanism embodied in this invention is carried internally of the drum and is adapted to engagethe inner' periphery of band 16. Such mechanism consists essentially of a plurality of segmental brake shoes, each having a strip of frictional brake material 19 on their outer surfaces. Means for mounting the shoes consists of equidistantly spaced pairs ofvradially projecting lugs 23 and 24. Asbest seen in` Fig. 2, each pair of these lugsfisprovided with aligned apertures 25, one or 'both of which may be screw threaded as at26 for the reception of pivotal pins 27 The brake shoes indicated by numerals 28 are formed at one end with inwardly extendingbosses'29y adapted to be received between the vpairs of lugs 23and 24, and such bosses have transverse apertures 30, through which is' passed the pins 27. Suitable bearings 31 may be used between the pins 26 and the apertures 30. Springs 32, seated in sockets 33, provided on the inner side ofthe shoes and haivingtheir outer ends bearing .against the hollow boss 14, are employed to maintain the brake shoes pressed into frictional engagelment atall times with the drum band 16,`

One of the main objects of the present in# vention is to provide a simply constructed shock absorber having an external rotatable brake. drum'and a'plurality of brake shoes c'o-operating therewith to Vretard the movement of` such drum in one direction. The herein described novel mechanism accomplishes this function in a very much more effective and improved manner over the lmechanisms of'previously'designed shock absorbers. Taking foreXampl'e, the arrangement of' one` of the shoes (in Fig. 1), together with its point/of pivotal mounting and the relative position of the brake band, it will be seen that the brake band'is concen tricaslly movable about its axis and about the outery periphery ofV the'friction surface of the brake shoes when the latter are in `normal 0r inoperative position. It will also be seen that'the pivotal'points -of the shoes and the outerperipheries thereof are of eccentric re`l lation. Y To aid inthe understanding` of the braking 'operation of the present' shoes cer" tain'characters are placed on Fig. 1. T designates thepoi'nt of tangent of the path of travel/of the brake band 16 relative" to the pivotal pointP of shoe A, andB anyv point on the outer periphery of said shoe to the right of' thefpoint T. Consequently,'if the point B be moved to the left the friction surface at that point of the shoe, due to the eccentric relation of the point P, will become wedged against the inner surface of the brake band 16 and cause a braking action of thefmovement of the brake drum. Likewise, thefentire outer surface of the brake shoe, on account of its construction, will be forced into tight engagement with the brake drum during its rotation to the left.

ln the reverse movement (to the right of the drawings), it will be obvious that such wedging or brakingaction of the shoes will be relieved, and only the pressure of springs 32 will be effective at that time. Inasmuch as itvisfound desirable to retard to alesser degree the sudden-movement of an axle toward the chassis ofy a. vehicle the springs 32 maybe designed to force the brake shoes into tight enough engagement with Vthe drum band 16 to suiiiciently brake such movement.

Further details in the construction of the embodiment of the invention shown in Figs. 1 and 2 consist of a dust plate 40 screwed to the rear face of bosses 23 and-a ange 41Ycircumferentially provided on member 14l in alignment with such bosses. For simplicity of construction the pins 27 extend through such plate and a lock nut 43 and washer vare secured on the outer end thereof. Plate 40 has an inturned annular flange vmember 42 which is adapted tooverlie the outer surface of the brake drum'band16, and thus prevent any dirt from enteringthe interior of the drum at that point. Mounted on the outer end 45 of bolt 12 is avdisk washer 46 adapted to prevent the drum 15- from moving laterally, there being interposed a ring of packing material 47' between the disk and the side 17 vof the drum. Contained inthe hollow portion of the boss 14, and surrounding the bolt 12, is spacing `tube48, against the end of which the disk 46 is held by nut 49. As seen in Fig. 2, the front edges 50 of the frictional brake material 19 are extended slightly beyond-the edge of the brake shoes, andthese edges 50 curve inwardly for the purpose of engaging t-he inner side of'platel.

It will be 'seen from the foregoing that the brake drum is held in assembled position only bythe 'brake shoes, and by the rounded ends 50of the friction unit, andthe disk washer 46, which construction 'is very simple and permits the self-aligning of the brake drum without difficulty. s

I have shown in Figs.l 6 and 7 amodilication-ofthe embodiment described above by which adjustment may be given to the pressure of springs 32 to compensate for the wear of the friction materialen the brake shoes. ln such modification, the forward end 100 of the-hub member 14 is provided on its exterior with a cylindrical-bearing surface 101 upon which `is rotatablymounted an annular sleeve 102 of an adjustingmember 103. The outer Cil surface of sleeve 102 is provided with a series of equidistantly spaced cam lugs`104 against which the inner ends of springs 32 bear, it

being obvious that the tension or pressureof 5 the springs may be increased by merely rotating the member 103 to present a higher portion of the cams in engagementwith such springs. The outer end of member 103 is reduced in size and has a hole 105 therein through whichis passed the end of the bolt 12.

To facilitate the adjustment of member 103 from the exterior of the shock absorber,

the outer reduced end of said memberis non- 15 parts in adjustment, a nut 107v is secured on 2O olt 45 outside the washer, thus serving to firmly hold the sleeve 102 on the hub from rotation. It will further be 'seen that by the use of the construction described above, the spacer tube 48 may be eliminated, in which case the adjustable member 103 serves to Vlimit the lateral movement of the washer 46.

The modified form of shock absorber illustrated in Figs. 3 and 4 embodies the use of practically the same construction ofbr'aking mechanism as inthe previously described shock absorber of the invention, comprising asimilar hub attaching member 50 adapted to be mounted on the side of a vehicle chassis by means of bolt 51y anchored therein. Member 50 isv formed with an outwardly projecting hollow boss 52 which is provided at its outer end with an interior cylindrical-bearing surface 53,'in which'is rotatably seated an inwardly projecting annular hub or journal 54 formed upon adrum 55.

The drum 55 is also provided with an inturned flange portion 56 at its outer rim, which flange serves as a brake band similar to the band 16, as will presently appear. lMeans 45 for retaining thedrum in place on the bearing 53 is shown in the form of a disk 57 mounted on the forward projecting end 53 ofvbolt 51. There may be also utilized a spacer tube 59 interiorly fitted within the hollow boss 52 to prevent disk 57 from bearing too tightly against the drum.

The braking mechanism is here also carried internally of the drum, such mechanism comprising two yor more brake shoes 60 pivotally 5 mounted at one end upon pins 61, which are secured in pairs of lugs 62 and 63, projecting radially from boss 52. Each brake shoe is arcuate in form, with its outer surface con- Y centric to the band portion 56 of the drum 55, and has pads or layers 64 of friction brake material attached to said outer surface. It is found that in forming the shoe as shown in Fig. 4 with its ends terminating substantially diametrically of the brake drum, the greatest 65 amount of friction or wedging action occurs 'tends tov rotate they 'drum 55 to the tend t0 hold the endsaway from the desired wedging action. Springs 65, received inthe 'n sockets 66 provided in the inner sides of the shoes 60 and engaging th-e boss 52, tend to keep the brake .shoes pressed outwardly intol engagement with the inner periphery of the drum. These brake shoes co-operate with the brake drum upon rotation of the drum to the left to retard such rotary movement, as has been hereinbefore 4described with relation to the shock absorber of Figs.'1 and 2, but in this embodiment the shoes are not adapted to exert anybraking action upon the drum in its reverse movement.

Means for connectingthe brake drum 55 to the axle of a vehicle is shown in the form of a the usual strap 7 0,'which is wrapped around the exterior of the brake band 56 and has its end attached to said drum as at 71. The other end of the strap is attached in any well known manner, not shown, tothe axle of the vehicle, it being readily VVunderstood that upon the separation ofthe vehicle chassisland axle the strap will rotate the drum 55 to the left, and consequently fthe braking 'mechanism will operate to retard such separation.

It is necessary to provide means for taking up slack in the strap` which results whenkthe axle is moved towards the chassis. For this purpose I providea helical spring 73, coiled around the tubular spacer 59, and havingy its ends engaged yin suitable slots 74 and 75 formed in the attaching member 50 and in the brakedrum 55 respectively. Spring 73 right against'the pull of theV strap.'y 1 l 1 Acover plate 76' is mounted outside the ico brake drum 55 on the end yof thebolt 51v to .enclose the strap and other operating mechr78 is secured to the rea-r. face of boss'lugs 62,

which,with plate 76, completely encloses the braking mechanism.

Fig. 8 illustrates on a greatly enlarged scale, the convergence between the inner surface of the brake drum and the outer adjacent surface of the brake shoe Ypivotal bearing. Ashas been previously described, as the .drum is moved to the left (of the drawings) the brake shoe, on account of its frictional engagement therewith, will be moved to wedge-between these two 'convergent surfaces, which effects a braking actionon the rotary movement of the drum.

Other modes of applying the principle `of my invention may be employed instead of the one explained, change being made asfreisi CFI

gards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed. y

I therefore particularly point out and distinctly claim as my invention 1. A rebound check for spring vehicles comprising in combination with a drum mounted rotatably on one of the two vehicle members between which the vehicle springs react, a spring vconnected to the drum for being 'tensioned by the vrotation of the drum in one direction and for rotating the drum inthe opposite direction by its reaction; means connecting the drum with the other vehicle member for rotating the drum in the direction for tensioning the spring by the separating movement of the two vehicle members; a brake shoe fitting and springpre'ssed against acircumaxial surface of the drum and meansfor varying at will the tensionof the spring pressure on the shoe.

2.'In the construction defined in claim l foregoing, the drum having a circumaxial flange and the brake shoe being mounted for riction bearing on the inner surface of said ange.

3. In th-e construction defined in claim 1 foregoing, the drum having a circumferential flange and the brake shoe being mounted for friction bearing on the inner surface of saidv flange, a stud axle on which the drum is rotatably mounted, the means for mounting the brake shoe being a'transaxial member non-rotatably engaged with the stud axle.

4. In the combination defined in claim l foregoing, a stud axle on which the drum is rotatably mounted, the drum having a cavity at one side, the brake shoe being mounted in said cavity, and a transaxial member nonrotatably engaged with the stud axle on which the shoe is mounted.

5. In the construction defined in claim l, a stud axle on which the drum is rotatably mounted, the drum having a cavity at one side, the brake shoe being mounted in said cavity and a transaxial membernon-rotatably engaged with the stud axle onV which non-rotatable member the brake shoe is mounted, and a spring carried by the stud axle reacting on the shoe for pressing it outwardly with respect to the axle for its friction bearing against the inner peripheral Wall of the said cavity.

6. In the construction defined'in claim l foregoing, a stud axle on which the drum is rotatably mounted, the drum having a cavity at one side, the brake also beingmounted in said cavity, and a transaxial member nonrotatably engaged with the stud axle on which member the shoe is mounted, a spring carried by the stud axle reacting on the shoe for-pressing it outwardly with respect to the axle for its friction bearing against the inner peripheral wall yof said cavityV and means 7. A rebound check for spring Vvehicles comprising in combination with a drum mounted rotatably on one of the two vehicle y members between which the vehicle springs react, a spring connected to the drum for being tensioned by the rotation of the drum in one direction and for rotating the drum in the opposite direction by itsvreaction; means connecting the drum with the other vehicle member for rotating the drum in the direction for tensioning the spring by the separating movement of the vehicle members; a stud axle on which the drum is mounted for rotation; a pair of brake shoes each carried non-rotatably by the stud axle movable radially with respect thereto in opposite directions, means for pressing the shoes oppo` sitely against the circumaxial surface of the drum;vand means for varying said pressure at will.

8. A rebound check for spring vehicles comprising in combination with a drum mounted rotatably on one of the two vehicle members between which the vehicle springs react; a spring connected to the drum for being tensioned by the rotation of the drum in one direction and for rotating the drum in the opposite direction by its reaction; means connecting the drum with the other vehicle member for rotating the drum in the direction for tensioningthe spring by the separating movements of the vehicle members; a stud axle on which the drum is mounted for rotation; a pair of brake slices pivotally carried by the stud axle for swinging about their pivots oppositely against the circumaxial surface of the drum, and means for pressing them thereagainst, the pivots of the two shoes being relatively remote in opposite direction from the axis of the stud axle and drum, both shoes trending from their pivots in the salne circumferential direction, whereby the rotation of the drum in one direction causes both shoes to hug the circumaxial surface of the drum for increasing friction and its rotation in the opposite direction causes both shoes to be relaxed as to their pressure on the drum for diminishing friction.

Signed by me this 29th day of October,

COUR'INEY N. MITCHELL. 

